You will probably also want to keep the new frogs in a small "quarantine" or "nursery" for a month or so before putting them in the vivarium. I use a Kritter-Keeper and seal the vents, except for the center feeding lid, with clear shipping tape. Just pur a layer of brown sphagnum on the bottom and throw in a couple of plant cuttings. I also keep one of the shipping cups on its side in there with a bit of extra water in it. This will give you a chance to observe each one, see that everyone is eating and remains healthy. Patrick Nabors advises separate containers for each new frog, but I don't do this unless there is some question of possible parasites and fecals need to be collected from a damp paper towel substrate.
The basement will be ideal. If raising the lights should still heat up the tank too much, you can always just blow a small fan between the lights and top of the tank.
I have spent some time in what is probably your general area, between Eureka and Garberville with a friend who lived down in the redwoods (in the 70's). At that time at least, there were some fantastic mushrooms growing in the woods. It might be fun to collect some mature caps and make spore-prints, blow the spores into your tank to see if any of them ever take hold and eventually fruit. If you use a little of the forest duff in your tank, you might also get some other fun surprises, and maybe even some "free food" for the frogs in the way of little isopods, fungus gnats, springtails, &etc. About the only possible problem you might have with this would be introducing slug or snail eggs, but these will be large enough that you can just remove them if they show up.
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Patty
Pahsimeroi, Idaho
D. auratus blue
D. galactonotus pumpkin orange splash back
D. imitator
D. leucomelas
D. pumilio Bastimentos
D. fantasticus
P. terribilis mint and organe
D. reticulatus
D. castaneoticus
D. azureus
P vittatus
P. lugubris